Advanced Materials Research Vols. 864-867

Abstract: Core-shell montmorillonite-TiO₂ colloids were prepared in a hydrothermal process and characterized with transmission electron microscope, powder X-ray diffraction analysis, Brunauer-Emmett-Teller analysis and UV-vis spectra. Afterwards, their photocatalytic activity was investigated under UV irradiation using methyl orange as a model contaminant. In addition, the stability of the core-shell montmorillonite-TiO₂ colloids was investigated by repeatedly performing methyl orange photocatalytic degradation experiments. The results indicate the as-prepared core-shell montmorillonite-TiO₂ colloids are a highly efficient photocatalyst for the degradation of organic dyes in water. And this photocatalytic activity remains almost unchanged after eight successive cycles.

Abstract: In this study, orange peel was utilized as low-cost adsorbent to remove furadan from aqueous solution by adsorption. All the experiments were conducted at 30 °C to investigate the effects adsorbent dose, pH value and ionic strength on furadan adsorption and the optimal experimental conditions were ascertained. The percentage removal (%) increased with an increase in the initial adsorbent dose, whereas the value of q_e (mg.g^-1) decreased with an increase in the initial adsorbent dose .The curve of q_e and removal percentage can be divided into two stages (first stage: adsorbent dose between 0.05 and 0.20 g; second stage: adsorbent dose between 0.25 and 0.35 g). The value of q_e (mg.g^-1) for OP increased as the pH increase, and reached the maximum at pH 7.81, then decreased as the pH continue increasing. The initial pH value of furadan solution should be controlled between 7.50 and 8.00. In addition, the value of q_e decreased sharp as the initial Na⁺ concentration was increased from 0 to 2.5 ×10^-3 mol.L^-1, then, the value of q_e was not significantly altered beyond the initial Na⁺ concentration 2.5×10^-3 mol.L^-1. Therefore in order to enhance adsorption efficiency of furadan by OP, the subsequent experiments were carried out in the low ionic strength of furadan solution.

Abstract: Various chemicals emerge in environment and exist as mixtures with different forms and concentrations. Toxicity interaction by mixtures may pose potential hazards and risks to the environmental safety and human health. Recent data show that toxicity interaction within ionic liquid (IL) mixtures related with some certain component. However, how to determine the specific component in a mixture is not an easy work and needs more researches about it. Therefore, we investigated the toxicity of twelve groups of mixtures by using three ILs and one pesticide aldicarb as mixture components. Four binary and eight pseduo-binary mixtures were designed by equivalent effect concentration ratio ray method using EC₅ and EC₅₀ of individual component. The toxicities of single chemicals and these mixtures to a freshwater photobacterium Vibrio qinghaiensis sp.-Q67 were determined by using the microplate toxicity analysis method. Toxicity interaction within mixtures were determined based on an additive referrence model, concentration addition (CA). The results showed that three binary IL mixture exhibited additive action and one antagonism. Interstingly, most pusedo-mixtures of aldicab and binary IL mixture exhibited cleary synergism especialy when they were mixed in the ratio of components EC₅.

Abstract: The 1.5t/h algae and bacteria wastewater with high concentration was treated by hydroxyl radical (OH) produced by a strong ionization discharge. In this paper, the feasibility of kill bacteria and alga by OH was investigated, and effects of OH concentration, treatment time and pollution initial concentration on degrading microorganisms by OH were investigated in detail. The results indicated that the treatment process was effective in the degradation of the bacteria and alga at the initial pH value of 7.1, OH dosage of 2.33mg/L, the initial microcystis aeruginosa concentration of 10⁶/mL and the initial bacterial dosage of 10⁶cfu/mL, the bacteria and alga degradation rate reached 99.99% at 303K after 15min treatment. The results provided a theoretical basis for the OH treatment of microbial contamination in drinking water in large-scale.

Abstract: Bosten Lake was the largest inland freshwater lake in China. It is facing with a series of ecological problems nowadays. The phytoplankton and water samples of seventeen sampling sites in Bosten Lake were collected in September 2012. Results show that sixty-four species (genera) of phytoplankton, which belong to six phyla, are identified. The community structure of phytoplankton is dominated by Chlorophyta. The mean cell density of phytoplankton in whole lake is 8179.01×10⁴cells·L^-1 and Cyanophyta accounts for 94.71%. The dominant species are Chroococcus sp. and Synedra acus. In terms of Shannon-Wiener diversity index, Margalef richness index, Pielou evenness index and total nitrogen content, it is ascertained that trophic state of water body in Estuary and Pumping Station is between mesotrophication and eutrophication. While in the other districts, the water body is eutrophic. In addition, the eutrophic degree of water body in District IV is higher.

Abstract: The abundance of microphytoplankton and distribution of soluble heavy metal content of Xiangshan Bay were investigated in 2012. And the results showed that the abundance of microphytoplankton was 22×10⁴~502×10⁴ cells/m³ and the average cell abundance was 117×10⁴ cells/m³. The dominant species of microplankton were Coscinodiscus jonesianus. The abundance of microplankton cells reduced from middle port to the mouth of the port. The concentrations of Hg, As, Cu, Pb, Zn, Cd and total Cr of surface seawater in the whole areas studied were satisfied the class I water standard. Due to human activities, the concentrations of some areas in the bottom and middle of the port were relatively high and approximately satisfied class II water standard. The concentrations reduced from bottom to the mouth, however, most sea areas were still satisfied class I water standard

Abstract: The desulfurization wastewater is a kind of intractable wastewater which comes from the process of wet desulfurization. There are many shortcomings of traditional development methods. Desulfurization wastewater evaporation treatment in flue gas duct as a new processing technology. This approach of evaporating desulfurization wastewater by flue gas is feasible. The feasibility of the demonstration project of boiler flue gas treating wastewater on 4# boiler in Changshu Power Company limited was analyzed; the computational fluid dynamics (CFD) software FLUENT was adopted to simulated the pressure field and velocity field in the outlet flue pipes of air pre-heater. The concrete arrangement mode and the number of the spray lances were determined by calculations. The temperature of the flue gas is tested after the system was put into operation. The results showed that this technology can realize the desulfurization wastewater with zero discharge without hurting the work of electrostatic precipitator. The demonstration project is the first of its kind in domestic power industry; this study provides experiences and references of power plant desulfurization wastewater with zero discharge.

Abstract: Based on the investigation of measurement method of ammonium nitrogen (NH₄-N) desulfurization and denitrification wastewater (DDW) by distillation method, effects of pH, Cl/N and the initial concentration of NH₄-N on the removal of NH₄-N in DDW by sodium hypochlorite were studied. Results of parallel test and standard recovery test demonstrated good reliability and accuracy of the distillation method for the measurement of NH₄-N in DDW. The NH₄-N removal efficiency increased with pH from 5.0 and 8.0, and then decreased with pH higher than 8.0. Therefore, the optimum pH value was 8.0 with NH₄-N removal efficiency of 74.7%. NH₄-N removal efficiency was increased from 16.9% to 84.1% with Cl/N molar ratio rose from 1 to 5. The initial concentration of NH₄-N showed insignificant effect on the removal amount of NH₄-N, and the removed NH₄-N was about 12~13mg/L with the addition of 4.86mmol/L sodium hypochlorite.

Abstract: CO hydrogenation on carbon nanotubes (CNTs) supported Rh catalysts were conducted in a fixed bed reactor. The effect of reaction temperature, pressure and Mn additive on the catalytic performance was studied. The results revealed that temperature influent CO conversion and products selectivity significantly, while the effect of pressure was slightly. The temperature of 300 to 320 °C and a high pressure facilitate to synthesize ethanol with high efficiency. The highest ethanol and alcohol space time yield can be obtained on CNTs supported Rh catalyst containing 1.1% Mn.

Abstract: With copper and copper alloys widely used, copper corrosion has already caused huge economic losses. Super-hydrophobic surface treatment, a new kind of corrosion resistant technology, can effectively inhibit metal corrosion. This paper introduces the basic issues and the construction methods of copper and copper alloys super-hydrophobic surface. The effect of super-hydrophobic surface on the corrosion performance of copper and copper alloys is analyzed emphatically. Recent developments of super-hydrophobic surface and the existed technical barriers are also summarized in the paper.